Warfarin, acetylsalicylic acid and risk of incident atrial fibrillation in patients with heart failure and sinus rhythm: A meta-analysis

摘要

We have read with interest the letter endorsed by Lin and colleagues. They have raised the possibility that warfarin may reduce the risk of ischemic stroke by decreasing the incidence of atrial fibrillation (AF) in patients with heart failure and sinus rhythm. This hypothesis was based on a qualitative analysis of WASH, HELAS, WATCH and WARCEF trial results. To further explore this hypothesis, we performed a random effects meta-analysis of those 4 trials (n = 3.618 patients) to derive a pooled estimate of AF incidence (Fig. 1). Results showed a significant 36% odds reduction in the rate of AF in warfarin group in comparison to acetylsalicylic acid (odds ratio 0.74; 95% confidence interval: 0.55-0.99) without statistical heterogeneity (I2 = 0%). In absolute terms, the average number of patients needed to treat with warfarin (for 2.9 years) to prevent a single case of AF, in comparison to acetylsalicylic acid, is 64 (95% confidence interval: 36-1685). The direct comparison between warfarin or acetylsalicylic acid vs. control (placebo or no antithrombotic treatment) documented no significant difference, although the small number of evaluated patients and events limit the ability to draw robust conclusions. Nevertheless, there was a trend towards an increased incidence of AF in patients treated with acetylsalicylic acid in the latter comparison.